Function not_gadget 

pub fn not_gadget<W>() -> LogicGadget<W>
where
    W: Clone + Default + From<i32> + Zero,

Create a NOT gate gadget.

2-variable SpinGlass: input at index 0; output at index 1. Ground states: (0,1), (1,0) corresponding to valid NOT.

J = [1] for edge (0,1) h = [0, 0]